The present application is directed to fuel cells and more particularly to fuel cell structures and methods of manufacturing the same. Presently, components used in the manufacturing of fuel cells, such as flow fields, gas diffusion electrodes (GDEs), and electrolytic membranes (EM) are built separately as discreet elements and laminated together during an assembly process. This existing manufacturing process limits the structures of the elements to that which can be made individually at a reasonable cost, which in turn limits performance of resultant fuel cells.
A particular description of a fuel cell is U.S. Pat. No. 6,149,810 to Gonzalez-Martin et al., issued Nov. 21, 2000, which is directed to fuel cells having membrane with internal passages formed in bulk, being used to supply cooling water to the system. Particularly, the patent states that it describes a proton exchange membrane for use in electrochemical cells having internal passages parallel to the membrane surface, comprising permanent tubes preferably placed at the end of the fluid passages. The passages in the membrane extend from one edge of the membrane to another and allow fluid to flow through the membrane and give access directly to the membrane.
Another fuel cell design is described in U.S. Patent Application Publication No. US 2005/0112433 A1, to Apte et al., published May 26, 2005, which addresses the problem of mechanical failure in thin electrolytes. One embodiment is directed to varying the thickness of the electrolyte and positions at least either the anode or cathode in a recessed region to provide a short travel distance from ions traveling from the anode to the cathode or from the cathode to the anode. The second embodiment employs a uniquely-shaped manifold cover to allow close positioning of the anode to the cathode.
To improve the usefulness of fuel cells, it is considered desirable to be able to manufacture a fuel cell as a monolithic device with microstructures and thin and thick films optimized for high performance.